1. Field of the Invention
The present invention relates to a carton and, more particularly, to an easy open carton that can easily be torn to form an opening for exposing an interior thereof.
2. Description of the Related Art
FIG. 1 shows a conventional easy open carton 8 including two tear lines 81. Each tear line 81 includes a succession of spaced cut lines 811 each extending from an inner face through an outer face of the carton body of the easy open carton 8. A tear portion 82 is formed between the tear lines 81 and can be pulled by a user along the tear lines 81. Thus, the tear portion 82 can be torn from the easy open carton 8 to form an opening 83, permitting access to objects received in the easy open carton 8. An example of such an easy open carton 8 is disclosed in U.S. Pat. No. 3,004,697.
However, the cut lines 811 of the tear lines 81 of the easy open carton 8 extending through the outer face of the carton body result in poor structural strength at the portions of the carton body including the tear lines 81, such that unexpected damage by a force occurs easily. As an example, a portion of the tear lines 81 could break when the easy open carton 8 is pulled or inadvertently impacted during transportation, not only adversely affecting the appearance integrity of the easy open carton 8 but losing protection of the objects in the easy open carton 8. As a result, the objects in the easy open carton 8 are apt to be contaminated or to fall out of the easy open carton 8, adversely affecting the quality of the objects and causing loss.
FIG. 2 shows another conventional easy open carton 9 including an adhesive tape 91 bonded to an inner face of a portion of the carton body to be torn away. A pull tab 92 is provided on an outer face of the carton body. A user can pull the pull tab 92 to form a tear portion 93 on the carton body, assuring the tear portion 93 to be separated from the carton body along the tearing path to which the adhesive tape 91 is bonded to the carton body. An example of such an easy open carton 9 is disclosed in Taiwan Patent Publication No. 194682 entitled “TAPE AUTOMATIC BONDING MACHINE FOR TEARING OPEN PAPERBOARDS (CORRUGATED BOARDS)”.
Since the outer face of the easy open carton 9 does not have cut lines, the structural strength of the easy open carton 9 will not be adversely affected by the tear function, reducing the risk of unexpected damage by an external force.
However, in addition to the cost of paperboards, production of the easy open carton 9 also involves the adhesive tape 91, leading to an increase in the overall costs. Furthermore, securely and neatly bonding of the adhesive tape 91 to the inner face of the carton body during production of the easy open carton 9 requires a skilled worker or a special bonding machine. Of more importance, due to the difficulties in providing a curved bonding path for the adhesive tape 91, it is almost impossible to obtain a non-rectilinear tearing path on the easy open carton 9, failing to meet various needs in use. Thus, the easy open carton 9 cannot replace the above easy open carton 8 shown in FIG. 1. As a result, many of the easy open cartons still use a structure similar to that of the easy open carton 8.
Thus, improvement to conventional easy open cartons is needed.